US5478549A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of nitric oxide
Assignee: Invista North America LLC
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Filing: 1994-12-15
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Granted: 1995-12-26
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Expires: 2014-12-15
Abstract
Abstract A process for the manufacture of nitric oxide by the Ostwald process where group VIII metal is recovered in a catchment trap, and the nitrous oxide is converted to nitrogen and oxygen by passing it through a bed of zirconium oxide at reaction temperature.
Inventors
- 👤 Theodore A. Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:55
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/06; B01J21/066; C; C01; C01B; C01B21/00; C01B21/20; C01B21/24; C01B21/26; C01B21/265
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
A process for the manufacture of nitric oxide by oxidizing ammonia in which the amount of nitrous oxide, i.e., N 2 O by-product is lowered, which comprises passing a gas stream containing ammonia and oxygen in contact with a catalyst containing a platinum group metal under conditions such that nitric oxide and nitrous oxide will be formed in the stream, then passing the stream in contact with a catchment trap where the platinum group metal oxide that was volatilized during the prior step is recovered, and then dispersing the stream through a bed consisting essentially of zirconium oxide where the stream contacts zirconium oxide and nitrous oxide in the stream is converted to nitrogen and oxygen.
Claim 2
Dependent Claim
116 words
A process for the manufacture of nitric oxide by oxidizing ammonia in which the amount of nitrous oxide, i.e., N 2 O by-product is lowered, which comprises passing a gas stream containing ammonia and oxygen in contact with a catalyst containing a platinum group metal under conditions such that nitric oxide and nitrous oxide will be formed in the stream, then passing the stream in contact with a catchment trap where the platinum group metal oxide that was volatilized during the prior step is recovered, and then dispersing the stream through a bed consisting essentially of zirconium oxide where the stream contacts zirconium oxide and nitrous oxide in the stream is converted to nitrogen and oxygen.
Claim 3
Dependent Claim
24 words
The process of claim 1 in which the temperature of the bed consisting essentially of zirconium oxide is at or above 600 degrees C.
Claim 4
Dependent Claim
32 words
The process of claim 1 in which the bed consists essentially of zirconium oxide pellets that are cylinders having a diameter of approximately 1/8 inch and a length of approximately 1/8 inch.
Claim 5
Dependent Claim
30 words
The process of claim 1 in which the catalyst contains platinum and also contains at least one other Group VIII metal selected from the group consisting of rhodium and palladium.
Claim 6
Dependent Claim
13 words
The process of claim 1 in which the catchment trap contains palladium components.
Claim 7
Dependent Claim
30 words
The process of claim 1 in which the gas stream containing ammonia and oxygen is preheated to at least approximately 270 degrees C before contacting the platinum group containing catalyst.
Claim 8
Dependent Claim
124 words
A process for the manufacture of nitric oxide by oxidizing ammonia in which the amount of nitrous oxide, i.e., N 2 O by-product is lowered, which comprises passing a gas stream containing ammonia and oxygen in contact with a catalyst containing a platinum group metal under conditions such that nitric oxide and nitrous oxide will be formed in the stream, then passing the stream in contact with a catchment trap where the platinum group metal oxide that was volatilized during the prior step is recovered, and then dispersing the stream through a bed that consists of pellets that are an inert substrate coated with zirconium oxide where the stream contacts zirconium oxide and nitrous oxide in the stream is converted to nitrogen and oxygen.
Claim 9
Dependent Claim
124 words
A process for the manufacture of nitric oxide by oxidizing ammonia in which the amount of nitrous oxide, i.e., N 2 O by-product is lowered, which comprises passing a gas stream containing ammonia and oxygen in contact with a catalyst containing a platinum group metal under conditions such that nitric oxide and nitrous oxide will be formed in the stream, then passing the stream in contact with a catchment trap where the platinum group metal oxide that was volatilized during the prior step is recovered, and then dispersing the stream through a bed that consists of pellets that are an inert substrate coated with zirconium oxide where the stream contacts zirconium oxide and nitrous oxide in the stream is converted to nitrogen and oxygen.
Claim 10
Dependent Claim
18 words
The process of claim 7 in which the pellets also contain a stabilizing amount of calcium or yttrium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-25 | 1999-06-26 | 1999-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-25 | 2003-06-26 | 2003-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-25 | 2007-06-26 | 2007-12-26 | $7700.00 | Window Closed / Lapsed |